NCTM Standards- 1988
Learner.org- Representation Session Grades 3-5- http://www.learner.org/courses/teachingmath/grades3_5/session_05/index.html
Learner.org- Representation Session Grades 6-8- http://www.learner.org/courses/teachingmath/grades6_8/session_05/index.html
Mathematics education research embracing arts and sciences_Presmeg
Representations, Inscriptions, Descriptions and Learning A Kaleidoscope ofWindows_Kaput_98


Representation
Font, Godino, D'Amore-
Representation is characterised using abstract correspondence between two entities which are put in some referential relation one against another by an actor or an observer, “that deliberately pays no attention to what kinds of things are involved in the correspondence” (Kaput, 1998, p. 266).